<template>
  <div class="demo-block"
       :class="[blockClass, { 'hover': hovering }]"
       @mouseenter="hovering = true"
       @mouseleave="hovering = false">
    <div class="source">
      <slot name="source"></slot>
    </div>
    <div class="meta"
         ref="meta" :style="{'padding':isExpanded?'10px':''}">
      <div class="description"
           v-if="$slots.default">
        <slot></slot>
      </div>
      <div class="highlight">
        <slot name="highlight"></slot>
      </div>
    </div>
    <div class="demo-block-control"
         ref="control"
         :class="{ 'is-fixed': fixedControl }"
         :style="{'width':width}"
         @click="isExpanded = !isExpanded">
      <transition name="arrow-slide">
        <i :class="[iconClass, { 'hovering': hovering }]"></i>
      </transition>
      <transition name="text-slide">
        <span v-show="hovering">{{ controlText }}</span>
      </transition>
      <el-tooltip effect="dark"
                  :content="langConfig['tooltip-text']"
                  placement="right">
        <transition name="text-slide">
          <!-- <el-button v-show="hovering || isExpanded"
                     size="small"
                     type="text"
                     class="control-button"
                     @click.stop="goCodepen">{{ langConfig['button-text'] }}</el-button> -->
        </transition>
      </el-tooltip>
    </div>
  </div>
</template>


<script>
import { stripScript, stripStyle, stripTemplate } from "../util";
export default {
  data () {
    return {
      codepen: {
        script: "",
        html: "",
        style: "",
      },
      width:"auto",
      hovering: false,
      isExpanded: false,
      fixedControl: false,
      scrollParent: null
    };
  },

  methods: {
    // goCodepen () {
    //   // since 2.6.2 use code rather than jsfiddle https://blog.codepen.io/documentation/api/prefill/
    //   const { script, html, style } = this.codepen;
    //   const resourcesTpl = '<scr' + 'ipt src="//unpkg.com/vue/dist/vue.js"></scr' + 'ipt>' +
    //     '\n<scr' + `ipt src="//unpkg.com/element-ui@${version}/lib/index.js"></scr` + 'ipt>';
    //   let jsTpl = (script || '').replace(/export default/, 'var Main =').trim();
    //   let htmlTpl = `${resourcesTpl}\n<div id="app">\n${html.trim()}\n</div>`;
    //   let cssTpl = `@import url("//unpkg.com/element-ui@${version}/lib/theme-chalk/index.css");\n${(style || '').trim()}\n`;
    //   jsTpl = jsTpl
    //     ? jsTpl + '\nvar Ctor = Vue.extend(Main)\nnew Ctor().$mount(\'#app\')'
    //     : 'new Vue().$mount(\'#app\')';
    //   const data = {
    //     js: jsTpl,
    //     css: cssTpl,
    //     html: htmlTpl
    //   };
    //   const form = document.getElementById('fiddle-form') || document.createElement('form');
    //   while (form.firstChild) {
    //     form.removeChild(form.firstChild);
    //   }
    //   form.method = 'POST';
    //   form.action = 'https://codepen.io/pen/define/';
    //   form.target = '_blank';
    //   form.style.display = 'none';

    //   const input = document.createElement('input');
    //   input.setAttribute('name', 'data');
    //   input.setAttribute('type', 'hidden');
    //   input.setAttribute('value', JSON.stringify(data));

    //   form.appendChild(input);
    //   document.body.appendChild(form);

    //   form.submit();
    // },
    scrollHandler () {
      const { top, bottom, left } = this.$refs.meta.getBoundingClientRect();
      this.fixedControl =
        bottom > document.documentElement.clientHeight &&
        top + 44 <= document.documentElement.clientHeight;
      this.$refs.control.style.left = this.fixedControl ? `${left-20}px` : "0";
      
       if(this.fixedControl){
         this.width = this.$refs.control.offsetWidth+10+"px";
       }
    },

    removeScrollHandler () {
      this.scrollParent &&
        this.scrollParent.removeEventListener("scroll", this.scrollHandler);
    }
  },

  computed: {
    lang () {
      return this.$route.path.split("/")[1];
    },

    langConfig () {
      return {
        "hide-text": "隐藏代码",
        "show-text": "显示代码",
      }
    },

    blockClass () {
      return `demo-${this.lang} demo-${this.$router.currentRoute.path
        .split("/")
        .pop()}`;
    },

    iconClass () {
      return this.isExpanded ? "el-icon-caret-top" : "el-icon-caret-bottom";
    },

    controlText () {
      return this.isExpanded
        ? this.langConfig["hide-text"]
        : this.langConfig["show-text"];
    },

    codeArea () {
      return this.$el.getElementsByClassName("meta")[0];
    },

    codeAreaHeight () {
      if (this.$el.getElementsByClassName("description").length > 0) {
        return (
          this.$el.getElementsByClassName("description")[0].clientHeight +
          this.$el.getElementsByClassName("highlight")[0].clientHeight +
          20
        );
      }
      return this.$el.getElementsByClassName("highlight")[0].clientHeight;
    }
  },

  watch: {
    isExpanded (val) {
      this.codeArea.style.height = val ? `${this.codeAreaHeight + 1}px` : "0";
      if (!val) {
        this.fixedControl = false;
        this.$refs.control.style.left = "0";
        this.removeScrollHandler();
        return;
      }
      setTimeout(() => {
        this.scrollParent = document.querySelector(
          ".page-component__scroll > .el-scrollbar__wrap"
        );
        this.scrollParent &&
          this.scrollParent.addEventListener("scroll", this.scrollHandler);
        this.scrollHandler();
      }, 200);
    }
  },

  created () {
    const highlight = this.$slots.highlight;
    if (highlight && highlight[0]) {
      let code = "";
      let cur = highlight[0];
      if (cur.tag === "pre" && cur.children && cur.children[0]) {
        cur = cur.children[0];
        if (cur.tag === "code") {
          code = cur.children[0].text;
        }
      }
      if (code) {
        this.codepen.html = stripTemplate(code);
        this.codepen.script = stripScript(code);
        this.codepen.style = stripStyle(code);
      }
    }
  },

  mounted () {
    this.$nextTick(() => {
      let highlight = this.$el.getElementsByClassName("highlight")[0];
      if (this.$el.getElementsByClassName("description").length === 0) {
        highlight.style.width = "100%";
        highlight.borderRight = "none";
      }
      this.width = this.$refs.control.offsetWidth+10+"px";
    });
  },

  beforeDestroy () {
    this.removeScrollHandler();
  }
};
</script>

<style lang="scss">
.demo-block {
  border: solid 1px #edf3f8;
  transition: 0.2s;
  margin-top: 10px;
  border-radius: 12px;
  box-shadow: 0 8px 12px rgba(235, 237 ,240,.69);
  background-color: #fff;
  overflow: hidden;

  &:hover {
    box-shadow:0 0 10px 0 rgba(196,206 ,232 , 0.4);
  }

  code {
    font-family: Menlo, Monaco, Consolas, Courier, monospace;
  }

  .demo-button {
    float: right;
  }

  .source {
    padding: 24px;
  }

  .meta {
    background-color: #fafafa;
    border-top: solid 1px #eaeefb;
    overflow: hidden;
    height: 0;
    transition: height 0.2s;
  }

  .description {
    padding: 20px;
    box-sizing: border-box;
    border: solid 1px #ebebeb;
    border-radius: 3px;
    font-size: 14px;
    line-height: 22px;
    color: #666;
    word-break: break-word;
    margin: 10px;
    background-color: #fff;

    p {
      margin: 0;
      line-height: 26px;
    }

    code {
      color: #5e6d82;
      background-color: #e6effb;
      margin: 0 4px;
      display: inline-block;
      padding: 1px 5px;
      font-size: 12px;
      border-radius: 3px;
      height: 18px;
      line-height: 18px;
    }
  }

  .highlight {
    pre {
      margin: 0;
    }

    code.hljs {
      margin: 0;
      border: none;
      max-height: none;
      border-radius: 0;

      &::before {
        content: none;
      }
    }
  }

  .demo-block-control {
    border-top: solid 1px #eaeefb;
    height: 44px;
    box-sizing: border-box;
    background-color: #fff;
    border-bottom-left-radius: 4px;
    border-bottom-right-radius: 4px;
    text-align: center;
    margin-top: -1px;
    color: #d3dce6;
    cursor: pointer;
    position: relative;

    &.is-fixed {
      position: fixed;
      bottom: 0;
      width:1000px
    }

    i {
      font-size: 16px;
      line-height: 44px;
      transition: 0.3s;
      &.hovering {
        transform: translateX(-40px);
      }
    }

    > span {
      position: absolute;
      transform: translateX(-30px);
      font-size: 14px;
      line-height: 44px;
      transition: 0.3s;
      display: inline-block;
    }

    &:hover {
      color: #409eff;
      background-color: #f9fafc;
    }

    & .text-slide-enter,
    & .text-slide-leave-active {
      opacity: 0;
      transform: translateX(10px);
    }

    .control-button {
      line-height: 26px;
      position: absolute;
      top: 0;
      right: 0;
      font-size: 14px;
      padding-left: 5px;
      padding-right: 25px;
    }
  }
}
</style>